physics pp. 1061–1063 Effect of doping Ca on polaron hopping

Abstract. From the transport studies in the bilayer manganites LaSr2−x Cax Mn2O7, we have found the variable-range hopping model proposed by Viret et al to be inadequate to describe the transport of charge in these materials. The polarons appear to hop to their nearest neighbors with an activation energy, which in part is dependent on the magnetic interactions in the lattice